This invention relates to a fluorine-containing AB-type block copolymer having a fluorine-containing polymer chain and a polymer chain having affinity for a resin.
It has been already known that a block copolymer is useful for modifying the surface or interface of a resin and making its effect persistent.
The fluorine-containing AB-type block copolymer of the present invention functions in such a manner that the fluorine-containing polymer chain is oriented to the surface or interface of the resin to be modified, while the polymer chain having affinity for a resin is fixed to the resin. Accordingly, it can be used in various fields in which excellent properties possessed by fluorine atoms such as corrosion resistance, water resistance, solvent resistance, chemical resistance, non-tackiness, peeling characteristic, low frictional characteristic, low abrasion, staining resistance, water repellency, oil repellency, weathering resistance, heat resistance, biological compatibility, etc. are desired to be imparted to a resin. Specifically, it can be used as a paint additive, resin additive, peeling agent, mold release agent, a water repellent, oil repellent or surfactant.
An attempt has heretofore been made to synthesize fluorine-containing block copolymers which are expected to have the above mentioned excellent surface or interface modification effect, but has not been successful with radical polymerization methods. Meanwhile, Japanese Laid-Open Patent Publication No. 221410 has proposed that a block copolymer containing a (per)fluoroalkylene group or (per)fluoroalkyl group can be synthesized by use of a polymeric peroxide or a polyazo compound.
However, when a fluorine-containing block copolymer is synthesized by the use of a polymeric peroxide or polyazo compound as mentioned above, the molecular weight of the resulting polymer can be controlled with difficulty and further homopolymers are by-produced whereby it is difficult to obtain a block copolymer of high purity.